The present invention relates to a device and method for terminating an automatic braking process in a motor vehicle and, more particularly, to a device for terminating in a motor vehicle, an automatic braking process which has been triggered by a control unit as a function of brake pedal actuation and which is terminated when a breaking-off criterion is fulfilled, the vehicle having a brake system in which a brake pedal force is transmitted via a pressure rod to a brake booster.
DE 40 28 290 C1 describes an automatic braking process which is triggered when a specific actuation speed of the brake pedal is exceeded and is terminated at least when the driver no longer acts on the brake pedal. Further criteria for initiating and terminating such an automatic braking process are illustrated in non-prepublished Patent Application DE-P. 43 25 940.5 where it is also proposed to detect the pedal force applied to the brake pedal by the driver and to terminate the automatic braking process as a function of this pedal force.
The detection of the pedal force in the brake pedal requires additional sensor and evaluation logic, which, particularly with a component which is safety critical, requires an additional design and development outlay.
An object of the present invention is to provide a device and method which ensures reliable switching off of the automatic braking process but only with a low additional outlay.
The foregoing object has been achieved in accordance with the present invention by detecting the relative movement between the pressure rod of the brake system and a component which can be moved with respect thereto within a defined movement play. The detection of the relative movement of the component with respect to the pressure rod takes place by two control switches, i.e. a make contact and a break contact, which are actuated via a common switching cam. A switching process of the control switches takes place whenever the brake pedal is moved in the direction of its rest position. If a switching process which corresponds to this relative movement takes place during an automatic braking process the braking process is terminated.